Examples inaccurate carbon dating
The coral record verifies that radiometric methods are accurate. For the purposes of assessing accuracy, each of the methods is assumed to be applied in accordance with the established methods and technology.By analogy, a stop watch will not keep accurate time if it is not wound, if it is not in good repair, or if the operator forgets to press the button.C14 is continually being created and decaying, leading to an equilibrium state in the atmosphere.
Age estimates can be cross-tested by using different isotope pairs.
Results from different techniques, often measured in rival labs, continually confirm each other.
other isotope pairs cover intermediate time periods between the spans for carbon 14 and uranium.
Some radiometric dating methods depend upon knowing the initial amount of the isotope subject to decay.
Other methods do not require knowing the initial quantities.
For example, potassium decays into two different isotopes of argon having different half-lives.
Measuring the ratio of C14 to C12 and C13 therefore dates the organic matter for periods back to about eight half-lives of the isotope, 45,000 years.
After a long enough time the minority isotope is in an amount too small to be measured.
Every few years, new geologic time scales are published, providing the latest dates for major time lines.